1. Thermomechanical treatment increases the working life of chisels by 20–30% in cutting quenched steel. 2. The optimum deformation temperature of the head of the chisel is 500° C. Cooling below 500°C decreases the ductility of the metal and leads to the formation of cracks during deformation. 3. The effect of thermomechanical treatment consists in the change of the fine structure of the steel and in the type and distribution of dislocations.